1. Field of the Invention
The present invention is related to a method for controlling a spindle motor of an optical storage device, and more particularly to a method for controlling a spindle motor in accordance with a time length for passing through defect.
2. Description of Related Art
According to the present optical storage technology, the control modes for a spindle motor are as follows. One is CAV (Constant Angular Velocity) mode, in which a compact disc may adopt an identical rotation rate from inner to outer circles for improving the reading speed so that the more data read on the outer circles per unit time, the faster the reading speed. Another is CLV (Constant Linear Velocity) mode, in which owing to a spiral structure of the compact disc, the outer circle with longer circumference will have a faster reading speed as compared with the inner circle so that if it intends to maintain an identical reading speed, the rotation speed of the compact disc has to be gradually reduced with the laser pick-up head moving outwardly for maintaining an identical reading speed. Another is P-CAV (Partial CAV) mode, in which the CD-ROM drive reads the data in the CAV mode as reading a general CD and in the CLV mode as reading an audio CD for maintaining the stability of sound track picking-up. Still another is zone CLV mode, which will divide the CD into several zones from inner circle to outer circle, and in each zone, the burning speed will be maintained at a stable CLV speed.
However, in an optical storage system, when the reading CD is a defect CD, it is helpful that the defect is passed through quickly if the rotation speed of the spindle motor is increased so that the error of the focus servo or the tracking servo in the optical storage system can be reduced. Generally, multimedia player utilizes a low rotation speed CLV mode system for saving power consumption, and thus, as passing a bigger defect, it may sometimes have a serious mosaic or pause situation, or even can not be read and cause a crash that may seriously influence the playing quality. Furthermore, in the CLV mode, because the rotation speed is namely the data transmission rate, the data may have an error if randomly changing the rotation speed.
Therefore, since all the above-described CAV mode, CLV mode, P-CAV mode and zone CLV mode do not have any specific control mode for passing through the defect in an optical storage system, it still needs to be improved.